Pre-Stall Instability Distribution Over a Transonic Compressor Rotor
MetadataShow full item record
An investigation of the behavior of a transonic compressor rotor when operating close to stall is presented. The specific areas of interest are the behavior and location of lowfrequency instabilities close to stall. In running close to stall, compressors can begin to exhibit nonperiodic flow between the blade passages even when appearing to be operating in a stable steady-state condition. The data from the current rotor clearly show that low-frequency instabilities were present during steady-state operation when stall was approached. These frequencies are not geometrically fixed to the rotor and typically appear at 0.3–0.8 of the rotor speed. The presence of these low-frequency instabilities is known and detection is reasonably commonplace; however, attempts to quantify the location and strength of these instabilities as stall is approached have proved difficult. In the current test fast response pressure sensors were positioned in the case-wall; upstream, downstream, and over the rotor blade tips. Simultaneous data from the sensors were taken at successive steady-state settings with each being closer to stall. A time domain analysis of the data investigates the magnitude of the instabilities and their transient effect on the relative inlet flow angle. The data are also presented in the frequency domain to show the development and distribution of the instabilities over the rotor as stall was approached. Initially the instabilities appeared within the rotor row and extended downstream but at operation closer to stall they began to protrude upstream as well. The greatest amplitude of the instabilities was within the blade row in the complex flow region that contains phenomena such as the tip-vortex/normal-shock interaction and the shock/boundary-layer interaction. In addition as stall is approached the growth of the instabilities is nonlinear and not confined to one frequency.
RightsThis publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
Showing items related by title, author, creator and subject.
Arends, Christopher J (Monterey, California. Naval Postgraduate School, 1997-06);During the period June 1991 to August 1993, 107 Argus-tracked drifters, drogued to 15 m depth, were released in the Greenland, Iceland, and Norwegian (GIN) Seas. The drifter movements revealed the strong and spatially ...
Gannon, Anthony J.; Hobson, Garth V.; Davis, William L. (2012-01);Transient casing pressure data from a transonic rotor and rotor-stator stage measured using high-speed pressure probes embedded in the casewall over the rotor tips are analyzed. Using long data sets sampled at a high ...
Zeybek, Birol (Monterey, California. Naval Postgraduate School, 1997-03);A direct numerical simulation, based on spectral methods, has been used to investigate viscous, incompressible, steady, rotationally symmetric flow due to a sphere rotating with a constant angular velocity about a diameter. ...